Values of the slope dlnF2/dln(1/x) (lam_eff) from ZEUS and E665 data
    Table 3 of DESY 98-xxx

    The slope is measured by fitting F2 data at fixed Q2 with x < 0.01
    to the form Ax^(-lam_eff). The x range of each bin is given and <x> is 
    calculated from the mean value of ln(1/x) weighted with the statistical 
    errors of F2 in that bin.

    Q2       x_min       x_max        <x>       lam_eff    stat.     sys+      sys-
   GeV2                                                     err.   
   0.15    0.0000024   0.0000042   0.0000032    0.1337    0.0774    0.1889    0.1945
   0.20    0.0000032   0.0000085   0.0000055    0.1279    0.0357    0.0799    0.0832
   0.25    0.0000046   0.0017539   0.0000128    0.1360    0.0157    0.0404    0.0437
   0.30    0.0000067   0.0024604   0.0001139    0.1104    0.0074    0.0168    0.0220
   0.40    0.0000111   0.0052000   0.0006815    0.1146    0.0050    0.0148    0.0186
   0.50    0.0000213   0.0000462   0.0000288    0.1927    0.0501    0.1001    0.0970
   0.65    0.0000120   0.0052000   0.0018257    0.1139    0.0067    0.0160    0.0187
   0.90    0.0000190   0.0089330   0.0038381    0.1468    0.0050    0.0127    0.0140
   1.30    0.0000280   0.0089330   0.0023980    0.1518    0.0063    0.0142    0.0139
   1.90    0.0000390   0.0089330   0.0018283    0.1597    0.0079    0.0145    0.0131
   2.50    0.0000540   0.0089330   0.0013148    0.1785    0.0095    0.0156    0.0140
   3.50    0.0000630   0.0089330   0.0006105    0.1778    0.0123    0.0226    0.0182
   4.50    0.0001000   0.0005400   0.0002036    0.2612    0.0200    0.0417    0.0402
   6.50    0.0001000   0.0040000   0.0007896    0.1919    0.0051    0.0158    0.0117
   8.50    0.0001600   0.0016000   0.0006690    0.2605    0.0121    0.0164    0.0198
  10.00    0.0001600   0.0063000   0.0015607    0.2258    0.0067    0.0148    0.0138
  12.00    0.0002500   0.0025000   0.0009705    0.2500    0.0139    0.0182    0.0197
  15.00    0.0002500   0.0063000   0.0019294    0.2489    0.0100    0.0155    0.0141
  18.00    0.0003900   0.0063000   0.0020761    0.2739    0.0100    0.0140    0.0129
  22.00    0.0004000   0.0100000   0.0033772    0.2727    0.0095    0.0173    0.0141
  27.00    0.0006300   0.0063000   0.0026690    0.3325    0.0151    0.0171    0.0144
  35.00    0.0006300   0.0100000   0.0036811    0.3076    0.0157    0.0129    0.0189
  45.00    0.0010000   0.0100000   0.0036934    0.2891    0.0204    0.0221    0.0167
  60.00    0.0010000   0.0100000   0.0047073    0.3423    0.0215    0.0090    0.0171
  70.00    0.0016000   0.0100000   0.0048279    0.3062    0.0320    0.0183    0.0234
  90.00    0.0016000   0.0100000   0.0052737    0.2734    0.0395    0.0456    0.0273
 120.00    0.0025000   0.0100000   0.0061788    0.3798    0.0590    0.0000    0.0022
 150.00    0.0025000   0.0100000   0.0062821    0.2584    0.0786    0.0038    0.0001
 200.00    0.0040000   0.0100000   0.0069944    0.2498    0.1260    0.0000    0.0025
 250.00    0.0040000   0.0100000   0.0079115    0.4517    0.1841    0.0077    0.0002